Low physiologic oxygen tensions reduce proliferation and differentiation of human multipotent mesenchymal stromal cells

<p>Abstract</p> <p>Background</p> <p>Human multipotent mesenchymal stromal cells (MSC) can be isolated from various tissues including bone marrow. Here, MSC participate as bone lining cells in the formation of the hematopoietic stem cell niche. In this compartment, the oxygen tension is low and oxygen partial pressure is estimated to range from 1% to 7%. We analyzed the effect of low oxygen tensions on human MSC cultured with platelet-lysate supplemented media and assessed proliferation, morphology, chromosomal stability, immunophenotype and plasticity.</p> <p>Results</p> <p>After transferring MSC from atmospheric oxygen levels of 21% to 1%, HIF-1α expression was induced, indicating efficient oxygen reduction. Simultaneously, MSC exhibited a significantly different morphology with shorter extensions and broader cell bodies. MSC did not proliferate as rapidly as under 21% oxygen and accumulated in G₁phase. The immunophenotype, however, was unaffected. Hypoxic stress as well as free oxygen radicals may affect chromosomal stability. However, no chromosomal abnormalities in human MSC under either culture condition were detected using high-resolution matrix-based comparative genomic hybridization. Reduced oxygen tension severely impaired adipogenic and osteogenic differentiation of human MSC. Elevation of oxygen from 1% to 3% restored osteogenic differentiation.</p> <p>Conclusion</p> <p>Physiologic oxygen tension during <it>in vitro </it>culture of human MSC slows down cell cycle progression and differentiation. Under physiological conditions this may keep a proportion of MSC in a resting state. Further studies are needed to analyze these aspects of MSC in tissue regeneration.</p

AVHRR NDVI Compositing Method Comparison and Generation of Multi-decadal Time Series —A TIMELINE Thematic Processor

Remote sensing image composites are crucial for a wide range of remote sensing applications, such as multi-decadal time series analysis. The Advanced Very High Resolution Radiometer (AVHRR) instrument provides daily data since the early 1980s at a spatial resolution of 1 km, allowing analyses of climate change related environmental processes. For monitoring vegetation condition, the Normalized Difference Vegetation Index (NDVI) is the most widely used metric. However, to actually enable such analyses, a consistent NDVI time series over the AVHRR time-span needs to be created. In this context, the aim of this study is to thoroughly assess the effect of different compositing procedures on AVHRR NDVI composites, as there is no standard procedure established. 13 different compositing methods have been implemented, daily, decadal and monthly composites over Europe and Northern Africa have been calculated for the year 2007, and the resulting data sets have been thoroughly evaluated according to six criteria. The median approach was selected as the best performing compositing algorithm considering all investigated aspects. However, also the combination of NDVI value and viewing and illumination angles as criteria for best-pixel selection proved to be a promising approach. The generated NDVI time series, currently ranging from 1981 - 2018, shows a consistent behavior and a close agreement to the standard MODIS NDVI product. The conducted analyses demonstrate the strong influence of compositing procedures on the resulting AVHRR NDVI composites

Seasonal Vegetation Trends for Europe over 30 Years from a Novel Normalised Difference Vegetation Index (NDVI) Time-Series—The TIMELINE NDVI Product

Remote sensing multi-decadal time-series provide important information for analysing long-term environmental change. The Advanced Very High Resolution Radiometer (AVHRR) has been providing data since the early 1980s. Normalised Difference Vegetation Index (NDVI) timeseries derived thereof can be used for monitoring vegetation conditions. This study presents the novel TIMELINE NDVI product, which provides a consistent set of daily, 10-day, and monthly NDVI composites at a 1 km spatial resolution based on AVHRR data for Europe and North Africa, currently spanning the period from 1981 to 2018. After investigating temporal and spatial data availability within the TIMELINE monthly NDVI composite product, seasonal NDVI trends have been derived thereof for the period 1989–2018 to assess long-term vegetation change in Europe and northern Africa. The trend analysis reveals distinct patterns with varying NDVI trends for spring, summer and autumn for different regions in Europe. Integrating the entire growing season, the result shows positive NDVI trends for large areas within Europe that confirm and reinforce previous research. The analyses show that the TIMELINE NDVI product allows long-term vegetation dynamics to be monitored at 1 km resolution on a pan-European scale and the detection of specific regional and seasonal patterns

Manuscripts As Sources of Linguistics and Cultural Studies. Current Issues – Methods – Problems. Proceedings of the post-graduate conference, Bamberg, 4.-5.12.2015

Der Tagungsband des Nachwuchskolloquiums „Handschriften als Quellen der Sprach- und Kulturwissenschaft. Aktuelle Fragestellungen – Methoden – Probleme“, das am 4. und 5. Dezember 2015 an der Universität Bamberg abgehalten wurde, vereint Beiträge aus nahezu allen dem Mittelalter zugewandten Disziplinen. Handschriftenbasierte Forschung aus der germanistischen Mediävistik, der historischen Sprachwissenschaft, Geschichte und Kunstgeschichte eröffnet eine breite Perspektive auf die mittelalterliche bis frühneuzeitliche Kultur und Gesellschaft, auf die sprachlichen Begebenheiten dieser Epoche, deren Manifestation durch Schreiber und die kodikologische und paläographische Analyse der Schreibumstände sowie die Chancen und Anforderungen einer zeitgemäßen Forschung durch die Nutzbarmachung informationstechnologischer Ressourcen und die Digital Humanities. Mit der vorliegenden Publikation werden Forschungsergebnisse von Nachwuchswissenschaftlerinnen und -wissenschaftlern, aber auch renommierten Fachvertreterinnen und -vertretern aus dem In- und Ausland dergestalt zusammengeführt, dass sich ein vielschichtiges Bild über die aktuelle Situation in der Forschung handschriftlicher Quellen ergibt.The proceedings of the postgraduate conference „Handschriften als Quellen der Sprach- und Kulturwissenschaft. Aktuelle Fragestellungen – Methoden – Probleme“, which was held on 4th and 5th of December 2015 at the University of Bamberg, unifies contributions from almost all medieval disciplines. Manuscript-based research from Germanic medieval studies, historical linguistics, history and art history opens up a broad perspective on medieval and early modern culture and society, on the linguistic characteristics of this period, their manifestation by scribes, the codicological and palaeographic analysis of their writing conditions and the opportunities as well as demands of contemporary research through the utilization of information technology resources and the Digital Humans. The present publication brings together the research results of junior scientists and renowned experts from Germany and abroad in such an extent, that a complex picture emerges of the status quo in research of manuscriptual sources

Challenges of Harmonizing 40 Years of AVHRR Data: The TIMELINE Experience

Earth Observation satellite data allows for the monitoring of the surface of our planet at predefined intervals covering large areas. However, there is only one medium resolution sensor family in orbit that enables an observation time span of 40 and more years at a daily repeat interval. This is the AVHRR sensor family. If we want to investigate the long-term impacts of climate change on our environment, we can only do so based on data that remains available for several decades. If we then want to investigate processes with respect to climate change, we need very high temporal resolution enabling the generation of long-term time series and the derivation of related statistical parameters such as mean, variability, anomalies, and trends. The challenges to generating a well calibrated and harmonized 40-year-long time series based on AVHRR sensor data flown on 14 different platforms are enormous. However, only extremely thorough pre-processing and harmonization ensures that trends found in the data are real trends and not sensor-related (or other) artefacts. The generation of European-wide time series as a basis for the derivation of a multitude of parameters is therefore an extremely challenging task, the details of which are presented in this paper

Erzählte Jenseitstopographie – Zur narrativen Realisation von Jenseitsräumen in der mittelhochdeutschen Legende Sankt Brandans

Der Beitrag zur erzählten Jenseitstopographie hat die Jenseitsexpedition des heiligen Brandan zum Thema. Nach einer Einführung zum Heiligen und seiner Legende widmet er sich der Frage danach, wie der Text den besonderen Erzählgegenstand einer Jenseitsreise narrativ bewältigt. Dies soll anhand eines Einblattdrucks einer mappa mundi illustriert werden, um schließlich die Frage danach zu stellen, welche Strategien zur narrativen Realisation der Verortung der als jenseitig konnotierten Orte innerhalb der Legende deutlich werden.This contribution to narrated topography of the afterworld deals with the voyage of St. Brendan. Following an introduction to the saint and his legend, it attends to the question of how the text deals with the unusual topic of a voyage to the afterworld as a narrative. This will be illustrated with an examination of a single-leaf woodcut of the 15th century of a mappa mundi; furthermore, the question will be posed which strategies the legend employs in the localization of places that are part of the afterworld

Flow and Turbulence over an Estuarine Dune − Large-Scale Flume Experiments

Die Küste, 93 - Online Firs

Die Bibliothek der frühen Neuzeit als Raum der Ideen - Kurzbericht zum Sommerkurs an der Herzog-August-Bibliothek in Wolfenbüttel

Im Bibelsaal der Herzog-August-Bibliothek.Foto: Christina Holzwarth Die Bibliothek als „Raum der Ideen“ stand im Mittelpunkt des diesjährigen Sommerkurses der Herzog-August-Bibliothek in  Wolfenbüttel. Im Bibelsaal der Herzog-August-Bibliothek, umgeben von Büchern, hatten in diesem Jahr insgesamt elf  Stipendiaten die Möglichkeit, die Bibliothek als Gegenstand gelehrter Auseinandersetzung in den Blick zu nehmen und gleichzeitig  zwei Wochen lang in der berühmten Herzog-August-Bibliothek zu fo..